Mobile devices with integrated telephones (e.g., smart phones) typically execute a proprietary operating system (OS) on top of which different software applications run, such as electronic mail, short message service, instant messaging, contact management, and electronic games, for example. However, writing applications for a proprietary OS can be difficult and time consuming, especially for content developers who typically do not have extensive training in software development. Some mobile device OS's allow applications to receive events from the OS that indicate, for instance, when a user has pressed a key on the mobile device or when a new message has arrived. Creating content that is sensitive to such events can require intimate knowledge of a mobile device OS's proprietary event model. Moreover, porting event-driven applications created for one proprietary OS to another can require a significant amount of additional software development for each OS the application is ported to.